Device for feeding rods or tubes in grinding machines or the like



May 26, 1942. J. E. BERGSTRUM DEVICE FOR FEEDING RO DS OR TUBES INGRINDING MACHINES OR THE LIKE Filed Dec. 21, 1939 3 Sheets-Sheet lDmvenibam- JOHN ERIK BERGSTRUM I by 01 M y 6,-1 .1. E. BERGSTROM2,234,257

DEVICE FOR FEEDING RODS OR TUBES IN GRINDING MACHINES OR THE LIKE FiledDec. 21, 1939 3 Sheets-Sheet 2 \nvc row IOHN ER\K BERGSTROM arrmen May26, 1942. J., E. B ERGSTRUM 2,234,257

DEVICE FQR FEEDING RODS OR TUBES IN GRINDING MACHINES OR THE LIKE FiledDec. 21, 1959 :5 Sheets-Sheet 5 JOHN ERIK BERG5TR 5M I I I a Patented 26, 1942i. 5 v I DEVICE FOR FEEDING RODS OR TUBES IN I GRINDING MACHINESOR THE LIKE John Erik Bergstrom, Halinstad, Sweden Application December21, 1939, Serial No. 310,374

In Sweden March 4,1939

s Claims. --(o1. 51%236) When grinding long rods or tubes it isnecessary to use a supporting channel or a so-called feeding table. Forsmall dimensions 'up'to about '15 mm. it issufficient to use asupporting channel that is displacea'ble in the vertical direction andprovided with movable or adjustable guiding strips for the work;

As soon as larger dimensions are to be ground, a simple supportingchannel is no'longer sufficient, and other and more eflicient means mustthen be used. Obliquely adjustable rollers have been used;'between whichthe rods or tubes have been supported. 'lfhe rollers run onball-bearings,

and the oblique adjustment of the rollers is eflfected tofacilitate thefeeding of the rods.

The above described auxiliary feeding devices are, however,connectedwith-the great disadvantage that only comparatively thinrods'may be led in centreless grinding machines depending on the pullingforce of the feed roller or regulating wheel used in'su'ch machines. Tomake possible a good and eflicient feed of the rods one has usedelectrically operated feeding tables,

in which obliquely adjustable supporting rollers arranged in pairs havebeen driven by an electric motor, the workresting in the gap between thesupporting rollers being arranged in pairs. Such a support for the rodshas the disadvantage that a certain bending action-is eifec'ted betweenthe rollers, which action may become u so strong that a spiral-formedmark in the form rollers right below the work, they may be obliquelyadjustedat'any time during the opera- 'tion,"the rate'of feed'beingthere'by adjustable from nought to a maximum,jand,-furthermore,-

the direction of feed of .thework may be reversed forth'and backdepending on whether the drive rollers "are obliquely adjusted to theone or the other side in relation to the work.

An'embodiment of the invention is illustrated on the accompanyingdrawings.

Fig. 1 shows a side elevation'view of a feeding table arranged accordingto the invention.

Fig. 2 shows a vertical cross-sectionof the same taken along the line11-111 in Fig. 1.

Fig. 3 shows a vertical longitudinal section through the end portion .ofthe table farthest away from the grinding'machine and taken in the planeIII-III in Fig. 2. r v

'Fig. 4 shows a vertical cross section along the line -IV-IV in Fig: 3;

of a shadow may be-observed onthe rod after I the grinding.

Furthermore these-known feeding tables have the disadvantage that therate-0f feed cannot be adjusted-or changed as desired without makingnecessary an intricate and expensive electric regulating device, andthey cannot be run both back and forth.

The present invention has for its object to develop afee'ding table forgrinding machines, particularly centreless grinding machines in whichthe rate of feed is'adjustable in a very simple manner, and wherein thedirection of feed may be reversed, and in which all of the abovementioned disadvantages are eliminated.

In the feeding tableaccording to the invention as in the knowntabl'es,rotary rollers supporting the'work are used, the axes of which rollersare obliquely adjustable in relation to the work for the purpose offacilitating or eifecting a feed of the work, but according to theinvention the said supporting rollers are arranged singly on a line oneafter another and support the work at or in the neighborhood of-thehigh- In Figs. 1 and 2,1 designates a feeding table which is supportedby the twostandards 2 and 3 so as to be elevated orlowered. aindicatesin Fig. 1 the bed of a centreless grinding machine. The standards Z and"3 each support a cylinder 4 in which a piston 5 supporting the table|:is fitted. Thepis'ton 5 iscarried by a vertical rod6 beingsecured to atransverse wall I in the piston.

The lower portion 8 of the rod; is threaded and screwed axially into abevel gear Sthat is rotatably journalled in a transverse yoke or bar 10being a part of the standards 2 and 3 respectively. The two bevel gears9 in the standards 2 and 3 are each in mesh with a bevelgear H, whichears are attached on a horizontal shaft I2 that extends between the twostandards 2 and 3. On the shaft l2 a hand wheel I 3 is secured. Byturning the hand wheel in the one or the other direction the rods 8,pistons 5 and the table I are raised or lowered. The table may be safelysecured on the adjusted level thereby that the cylinders 4 on top areprovided with a cut out slit I l so that the cylinders may beresiliently contracted on top by means of a screw 1-5 be'ing'threadedinto the boss [-5 so that the cylinder with sufficient friction willenclose the piston to secure the same in position.

The standard 2 differs from the standard 3 therein that in the upperportion of the standard the grinding machine. In Fig. 1 the table Ioccupies the limit position closest to the grinding machine. 7

2| designates a cylindrical rod that is being fed cured on the shaft 24by means of the pin 60, whereas the clutch member 48 is displaceablealong the shaft 24 within certain limits, for which purpose a pin 5|secured to the member 48 is passed through an oblong hole 52 in theshaft 24. Between the clutch member 48 and a nut 53 threaded on theshaft 2. spring 54 is arranged, the tension of which spring presses theclutch member48 towards the friction member 46 and the latter in itsturn against the clutch member 49. By turning the nut 53 which may belocked by the locking nut 55, the said tension may be varied andadjusted so that a desired sliding. may be obtained in the frictionclutch.

by the feeding table in the direction toward the 4 a grinding machine.number 'of drive rollers and journalled on the top side of the table,which rollers are so adapted that the rod will rest on the highest or inthe neighbourhood of the highestpoint of, the drive rollers. The driverollers 22 are, driven by a common shaft 24 running along. the table.Further, the work 2| is sustained by side bearing rollers 23 that,although parallel with the shaft 24 on opposite sides of the same. Whenthe arms 25 have been turned to The rod 2| is supported by a' 22arranged in alignment the desired position depending on the diameter ofthe work, the arms 25 are secured on the rods 26 which may be effectedthereby that the hubs of the arms are slit open at 28 and may be clampedon the rods 26 by tightening a screw 29. The rods 26 are supported bybrackets 30 secured on the top side of 'the table. 7

The rods 26 may be secured bya clamping device (not shown) similar tothe device 21, 28, 29 and secured to or integral with one of thebrackets 30. By loosening the clamping device of the rods 26, the lattermay be turned.

Thereby the positions of the side supporting rollers 23 on one or bothof the rods 26 may be adjusted simultaneously to suit the position ofthe regulating wheel of a centreless grinding'machine in relation to thework. This is of great importance, since it gives a possibility ofreadily adjusting the position of the work to the one or the other sideof the highest pointsof the drive rollers 22 to bring the work to thecorrect position on the feeding table in relation to the regulatingwheel and the grinding wheel.

Only the drive rollers 22, on the tops of which the work is resting, maybe mechanically driven.

g The end of the shaft 24 is, as indicated, journalled in a bracket 56secured to the feeding table.

' From the shaft 24 the drive power is transmitted to the drive rollers22 by the following means. The drive roller 22 is secured to a sleeve 51enclosing the shaft 24. On the inside said sleeve is provided withan'annular shoulder 58 or a pair. of projections arranged diametricallyoppositeone another, the face of said shoulder or saidprojectionsturned-towards the shaft 24 being cylindrical or sphericaland abutting against a'ring 59 secured on the shaft 24. Through theshaft 24 and the ring 59 a pin 60 is passed, the

'endsof which engage bores in the shoulder or projections 58 so that,when the shaft 24 is rotated, the pin brings the sleeve 51 and thus alsothe drive roller 22 along in the rotation,

By means of the described mounting of the sleeve 51 on the shaft 24 itis possible to position the axis of the drive roller 22 obliquely inrelation to the shaft 24. In doing so the sleeve is pivoted abouttheends of the pin 6|) in a plane through the centreline of the shaft 24perpendicular to the drawings. Thereby the axis of the drive roller willbeobliquely positioned also in relationtothe'centre line of the work sothat the frictional force acting between the drive roller and the workwill obtain a component in Their driving means is illustrated in Figs, 3and 4. Their driving shaft 24 is driven by the motor 3|, the housing ofwhich is secured to the flange 32 on the feeding table farthest totheright in Fig. 1. From the motor shaft 33 the drive power is transmittedby means of the gears-34, 35 to the shaft 36 and from thereby means ofthe worm gearing 31, 38 to the shaft 39 which by means of the gears46,4! drives the shaft 42 on which a second gear 43 (Fig. 3) is securedand in mesh with teeth 44 provided on the circumference of a frictionmember 45 which is loosely mounted on the shaft 24 so that it may berotated about as well as. displaced along the shaft 24. Thetwo endportions 46, 41 of the friction member 45 are bevelled and cooperatewith corresponding bevelled surfaces of two clutch members 48 and 49respectively. The clutch member 49 is rigidly sethe longitudinaldirection of the work, which component will exert a feeding action onthe work in the same way as in centreless grinding machines when theregulating wheel is obliquely positioned in relation to the work.

The drive roller 22 is mounted on a needle bearing 6|, the needles beingarranged between the sleeve 51'and an outer bearing ring 62 whichengages inside a cylindrical flange 63 on the drive roller. The ring 62is enclosed and carried by an anular-bracket 64 projecting upwards froma disc 65 mounted on the feeding table. The disc .65 isprovided with avertical pivot pin66 being journalled in the indicated way in thefeeding table. In one of the drive rollers 22 the lower end 61 of thepivot pin 66 is passed through a toothed segment 68 being clamped on thepivot end'6l by means of a nut 69 so that the toothed segment cannotturn on the pivot pin (Fig. 2). The teeth 69 ofthe toothed segment 68are in mesh with teeth 10 being cut in the end of a vertical rod "IIbeingrotatably journalled in the feeding tableand providedwith a handle12 for turning the sameiFigs. land 2)." The toothed portion of thetoothed segment '68 protrudes through a-slot 13 in the side wall of thefeeding table. Thetoothed-segment 68 supports a die "through whicha'regulating rod15 is passed and secured to the same, said regulatingrod being extended in. the longitudinal direction of the feeding tableand connected to levers (not 68 are secured in a similar way to thepivot pin 61 of the other drive rollers.

When the handle 12 is turned, the toothed segment 68 is turned and thusalso the pivot pin 66 on which the toothed segment is non-rotatablyattached. The regulating rod I transmits this motion to the pivot pins66 of the other drive rollers so that all the pivot pins are turnedsimultaneously and equal amounts. Thereby the discs 65 (Fig. 3) and theannular bracket 64 are turned about the centre line of the pivot pin 66.The bracket 64 will thus turn the drive roller 22 and the sleeve 51about the pin 60 by means of the bearing ring 62, the pin 60 beingcoaxial with the pivot pin 66. Thereby the drive rollers will occupy thesame oblique position in relation to the shaft 24 and the work 2|.

By the above described feeding device the advantage is also reached inconnection with centreless grinding machines that the work may be giventhe same rate of feed and peripheral velocity as the feed roller orregulating wheel of the grinding machine has or is giving to the work.Th side bearing rollers 23 may, if desired, also be made obliquelyadjustable in relation to the work in order to make the least possibleresistance to the feeding of the work.

The above described feeding table withaccessories is placed, on thefeeding side of the grinding machine and also on the delivery side ofthe same to receive and feed out the ready ground work.

Having now particularly described the nature of my invention and themanner of its operation what I claim is: V

1. Feeding table for feeding rods or tubes in grinding machinescomprising a table arranged at the side of the grinding machine, anumber of single rotary supporting rollers mounted on said table inalignment with each other and adapted to support the work in theproximity of the highest points of said supporting rollers, a number ofside bearing rollers being freely rotatably mounted on said table andadapted to abut against the work and to maintain the position of thelatter on top of said supporting rollers, a longitudinal straight andundivided common drive shaft for said supporting rollers passingcentrally through bores in said supporting rollers, means for rotatingsaid drive shaft, means for transmitting the rotary motion of the driveshaft to said supporting rollers, means for supporting and freelyrotatably journalling said supporting rollers independently of saiddrive shaft about axes, being perpendicular to the drive shaft, and acommon regulating rod intercon-.-

necting' said supporting rollers and adapted to turn themsimultaneously, even during the grinding operation, about said axesto'oblique positions in relation to the work.

2. Feeding table for feeding rods or tubes in grinding machinescomprising a table arranged at the side of the grinding machine, anumber.

of the drive shaft to said supporting rollers,v

standards displaceably supporting the'feeding table, means fordisplacing the feeding table in the vertical direction in relation tosaid standards to adjustthe level of the supporting rollers for works ofdifferent diameters, a set of side bearing rollers being freelyrotatably mounted on the feeding table on each side of the work andadapted to abut against the work and to maintain the position of thelatter on top of said supporting rollers, said side bearing rollersbeing pivotally mounted on arms, which on each side of the work aremounted on a common longitudinal rod to be adjustable simultaneously inthe transverse direction of the work to suit different sizes of thework.

3.Feeding table for feeding rods or tubes in' grinding machinescomprising a table arranged at the side of the grinding machine, anumber of single rotary supporting rollers mounted on said table inalignment with each other and adapted to support the Work in theproximityof the highest points of said supporting rollers, a

pendently of said drive shaft about pivot axes being perpendicular tosaid drive shaft, means for turning said supporting rollers'about saidpivot axes to oblique positions in relation to the work even during thegrinding operation, each supporting roller being rotated by said driveshaft by means of a pin device arranged and acting in a plane goingsubstantially through said pivot axis and adapted to allow said turningof said supporting rollers about said pivot axes independently of thedrive shaft.

JOHN ERIK BERGSTRDM.

